"""Fixed probe + a live cross-check against an independent grabber.

Stream is restarted every 30 s (a single long-lived one freezes). Every 60 s an
`import` grab of the same display is taken and compared: if the two disagree by
more than a few percent, the stream is lying and the run's numbers are void.
"""
import subprocess, sys, time, os
import numpy as np
from PIL import Image
W,H,SURF = 1280,720,45
LIMIT = float(sys.argv[1]) if len(sys.argv)>1 else 540
RESTART = 30
def _open():
    return subprocess.Popen(["ffmpeg","-loglevel","error","-f","x11grab","-draw_mouse","0",
        "-video_size",f"{W}x{H}","-i",":98","-r","4","-f","rawvideo","-pix_fmt","rgb24","-"],
        stdout=subprocess.PIPE, bufsize=W*H*3*2)
def independent():
    subprocess.run(["/usr/local/bin/screenshot","/tmp/xcheck.png"],capture_output=True)
    try: return float(np.asarray(Image.open("/tmp/xcheck.png").convert("RGB")).astype(int)[SURF:].mean())
    except Exception: return -1.0
p=_open(); n=W*H*3
t0=time.time(); seg=t0; lastx=t0; lastr=-1
frames=0; best=0; disagree=0; checks=0
while time.time()-t0 < LIMIT:
    if time.time()-seg > RESTART:
        p.kill(); p=_open(); seg=time.time()
    buf=p.stdout.read(n)
    if len(buf)<n:
        p.kill(); p=_open(); seg=time.time(); continue
    a=np.frombuffer(buf,np.uint8).reshape(H,W,3).astype(int)
    frames+=1
    sm=float(a[SURF:].mean())
    r,g,b=a[:,:,0],a[:,:,1],a[:,:,2]
    c=int(((g>130)&(g-r>45)&(g-b>45)).sum())
    if c>best:
        best=c
        if c>=400:
            Image.fromarray(a[SURF:].astype(np.uint8)).save("/sylph-home/re/shots/probe3-title.png")
            print(f"*** TITLE t={time.time()-t0:.1f}s glyph={c}",flush=True)
    if time.time()-lastx > 60:
        lastx=time.time(); checks+=1
        iv=independent()
        bad = iv>=0 and abs(iv-sm) > max(3.0, 0.15*max(iv,sm))
        if bad: disagree+=1
        print(f"  t={int(time.time()-t0):4d}s stream {sm:7.2f} | import {iv:7.2f} "
              f"{'<-- DISAGREE' if bad else 'agree'}   glyph {c}",flush=True)
p.kill(); dt=time.time()-t0
print(f"{frames} frames in {dt:.1f}s = {frames/dt:.2f} fps")
print(f"cross-checks {checks}, disagreements {disagree}")
print(f"max glyph {best}")